1. Field of the Invention
The invention relates to a linear recliner for an automotive vehicle seat that allows pivotal adjustment of a seat back relative to a seat cushion.
2. Description of the Prior Art
Automotive vehicles include seat assemblies for supporting occupants within the vehicle. Seat assemblies typically include a seat cushion and a seat back pivotally coupled to the seat cushion by a pivot pin for pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined seating positions. It is well known in the seating art to provide a linear-type recliner mechanism for providing selective, lockable adjustment of the seat back between any one of the plurality of reclined seating positions.
Linear recliners typically include a housing fixedly secured to the seat cushion. A rod or rack extends between one end pivotally coupled to the seat back below the pivot pin and an opposite end slidably carried in the housing for axial displacement within the housing during pivotal movement of the seat back about the pivot pin relative to the seat cushion. The rack typically includes a plurality of teeth formed on one side of the rack. A toothed pawl lockably engagable with the teeth in the rack is pivotally coupled to the housing for movement in and out of locking engagement with the rack. While engaged with the rack, the pawl prevents axial movement of the rack within the housing, and thereby, prevents pivotal movement of the seat back relative to the seat cushion. When the pawl is disengaged with the rack, the rack is allowed to slide axially within the housing and the seat back is allowed to pivot relative to the seat cushion. Typically, a lever-actuated cam is pivotally coupled to the housing for manually actuating the pawl in and out of engagement with the rack. A biasing member commonly extends between the cam and housing for biasing the pawl towards engagement with the rack. It is also known to include a help spring or second biasing member extending between the pawl and housing for biasing the pawl towards engagement with the rack. An example of such a linear recliner mechanism is shown in the U.S. Pat. 6,161,657, which issued to Zhuang et al. on Dec. 19, 2000.
It remains desirable to provide a simplified linear recliner design that utilizes a single biasing member for biasing the pawl towards locking engagement with the rack.
According to one aspect of the invention, there is provided a linear recliner assembly for a vehicle seat assembly for providing selective and lockable angular adjustment of a seat back pivotally coupled to a seat cushion. The linear recliner assembly includes a housing fixedly secured to the seat cushion. A rod extends between one end pivotally coupled to the seat back and an opposite end slidably carried within the housing for axial displacement therein during pivotal movement of the seat back relative to the seat cushion. The rod includes a rack of teeth formed therein. A pawl having a rack of teeth lockably engagable with the rack of teeth in the rod to prevent axial displacement of the rod within the housing is pivotally coupled to the housing for pivotal movement in and out of locking engagement with the rack of teeth in the rod. A cam is pivotally coupled with the housing and engagable with the pawl for moving the pawl in and out of locking engagement with the rod. An internal spring extends between the pawl and the cam for simultaneously biasing the pawl towards locking engagement with the rod and biasing the cam towards camming engagement with the pawl to urge the pawl towards locking engagement with the rod.